The invention relates to a method for operating a drive device that for the purpose of providing a driving torque comprises an internal combustion engine, which comprises a plurality of cylinders that during normal operation in each case supply a torque contribution, and at least one electric motor operatively connected to said engine.
In addition, the invention relates to a computer program product having a program code that is stored on a machine-readable storage medium for implementing the method mentioned above.
Methods of the type mentioned in the introduction are known from the prior art. By way of example, the unexamined German application DE 101 16 749 A1 illustrates a drive device that comprises an internal combustion engine and an electric motor that are controlled for the purpose of providing a driving torque, so that during normal operation each of the cylinders of the internal combustion engine supplies a torque contribution. Selected cylinders in the internal combustion engine are activated or deactivated in a separate operating mode for the purpose of providing a desired torque and achieving optimal performance and fuel economy.
It is additionally disclosed in the unexamined German application WO 01/59282 A1, in a diagnostic mode to perform a cylinder-individual measurement of torques or rather torque contributions output by individual cylinders and/or to measure combustion chamber pressures of individual cylinders as a characteristic operating variable, wherein the differences in torque delivered by individual cylinders are determined indirectly on the basis of an evaluation of the running smoothness of the internal combustion engine with the aid of a crankshaft rotation rate sensor.
A similar method is disclosed in the patent application EP 1 849 979 A2, in which a cylinder-individual fuel/fresh air mixture ratio is measured in the exhaust gas.